Amazon.com is the largest online retailer in the United States. They’ve made it incredibly easy to purchase millions of items that ship straight to your door. It’s convenient, saves some hassle in running errands, and often provides a way to buy items online for less than they cost in physical stores.

If you’re a frequent Amazon shopper, it makes good financial sense for you to maximize your savings when purchasing from the company. Here are five ways to can enjoy the convenience of shopping online with Amazon while saving even more money.

Share Your Prime Membership with Others in Your Household

Prime membership offers a serious perk for frequent Amazon shoppers: free two-day shipping on thousands of items. As a Prime member you also receive unlimited streaming of movies and video offered on Amazon Instant Video, and you can also borrow one e-book from the Prime library for free each month.

But Prime also costs users $99 for the year. That leaves you with lots of books to borrow, videos to watch, and purchases to make to get the free shipping if you want to offset the cost of membership.

Unless, of course, you share Prime membership with someone else and split the cost.

Amazon does allow you to add individuals onto your Prime account, but technically they should be members of your household. Here’s what Amazon says about sharing Prime benefits:

"Free or paid Amazon Prime members can share their shipping benefits with up to four additional family members living in the same household. If you purchase a Prime membership for a small business, you may invite up to four co-workers to shop with this corporate account."

It seems that the rules aren’t strict on the same-household stipulation. People sharing your Prime benefits can ship to multiple addresses, so it’s currently possible to add a friend who doesn’t live with you.

But Amazon may make this harder to do at any time, and you’ll need to decide for yourself if flouting the stated guidelines is something you want to do.

Get a Discount on Prime Membership

Certain groups enjoy Prime membership discounts, too.

If you’re a student with a valid .edu email address, you can sign up for a free trial of Amazon Student. You can also enjoy a discounted membership rate of $39 per year after your initial trial ends. Students can earn $10 to spend on Amazon each time they refer a friend to sign up, too.

If you’re a parent, you may want to give Amazon Mom a try. You’ll receive a three-month trial period that gives you the benefit of free shipping, but this service comes with a $99 yearly fee (just like Prime) that kicks in after your trial ends. Amazon Mom perks include big discounts on staples like diapers and other family essentials.

Look Through the Warehouse

The Amazon Warehouse, that is. Amazon has a section on its site called Warehouse Deals, where you can shop for open box and returned items and items that were damaged in transit. Because the items aren’t in “perfect” condition for retail sale, they’re offered here at discounted prices.

Purchase Everyday Items with Subscribe & Save

On many household essentials and grocery items, Amazon offers you the option to “subscribe” to the product and offers a discounted price if you do so. This is the retailer’s Subscribe and Save program.

Use Tools to Spot Additional Savings

If you’re a frequent online shopper and want to get serious about savings, there are two tools that will help you.

The first is a browser extension called Honey (which works with any online shopping cart, not just Amazon). Honey is a free tool that you can download and activate. Once you’ve loaded up an online shopping cart, you can use this tool to automatically search for and apply discount and promo codes.

The second is a website that helps you track prices of items on Amazon. This can help you identify sales cycles to help you score the best deal. The site is hard to forget thanks to its bizarre name: CamelCamelCamel.

And of course, you can always browse through Amazon’s own coupons to see if you can score additional savings.

Amazon is a great place for consumers to shop for almost anything imaginable. Make sure you get the very best deal and maximize your savings with these tips.

About the author: Kali Hawlk is a freelance writer and content manager currently working on building her business and becoming a full-time solopreneur. She's passionate about personal finance, careers and business, and all things Gen Y--and she writes about it all on her blog, Common Sense Millennial. An avid runner, she enjoys getting outside as often as possible when she's not immersed in blogging and helping other small businesses build and manage their online presence. Connect with her on Twitter @KaliHawlk.